[sanddrag]

Originally Posted by greencactus3

if you know how to use a servo, and understand the concept of resistors and how to read the lines you can make a clumsy mechanical real easy.

The problem with that is that you are not pulsing electricity, you are converting electricity into heat. The lower the voltage (speed) the higher the heat. You are making a constant power draw. The difference is the ratio of heat energy to kinetic energy.

So what I'm basically sayingis generally speaking a mechanical speed control will run down the battery faster than an electronic one, and it will get very hot. Electronic is better.